The construction of new buildings and the renovation of older buildings has often required the installation of numerous ducts for heating and air conditioning throughout the building. These ducts are either fastened to, or suspended from, the superstructure of the building, usually in attic, basement or utility spaces. The devices used for fastening and suspending such ducts have been numerous and varied. One of the major difficulties encountered in the use of such devices, however, has been the difficulty preassembling sections of duct to be installed and installing the fastening devices in the precise positions necessary properly to locate the duct assembly. Furthermore, it has usually been necessary to provide ancillary fastening devices such as nails, screws and bolts, in order to use the primary fastening devices. Finally, most such fastening devices, once in place, are semi-permanent, requiring extensive effort to adjust or remove if the initial installation proves to be incorrect.
It would therefore be desireable to provide a one-piece device, installable separately prior to the installation of the duct itself, and readily adaptable to the installation of large sections of duct assembled at a more convenient work location. Moreover, it would likewise be desirable to provide a single style of fastening device for sheet metal ducts regarless of the orientation of the fastening device. Finally, it would also be desirable to provide a readily adjustable, esily detachable and reusable fastening device for such ducts in the event of incorrect initial installation.